type timestamp = int

external start_simple: int -> unit = "caml_Pt_Start_Simple"
(* WARNING: do NOT use start if threading is enabled *)
external start: int -> (timestamp -> unit) -> unit = "caml_Pt_Start"
external stop: unit -> unit = "caml_Pt_Stop"
external started: unit -> bool = "caml_Pt_Started"
external time: unit -> timestamp = "caml_Pt_Time"
